Many different anchors and anchoring systems have been proposed, some of which are particularly suited to providing an anchor that may be embedded in concrete and to which other structure(s) may be attached. See, for example, EPC application published as No. 0029354 on May 27, 1981: Canadian patent application No. 2,703,627 published May 14, 2009, and U.S. Pat. Nos. 2,771,746; 4,339,217; 4,393,638; 4,770,580; 4,789,284; 4,968,200; 5,531,535; 5,352,077; 5,921,733; and 6,851,492; and U.S. Patent Publications: 2008/0310930; 2011/0062617; and 2012/0192404.
The common theme in these anchoring systems is to provide some form of undercut in the bore hole in which the anchor is to be secured and expand a part of the anchor to substantially fill the undercut area. In some cases, the anchor itself is provided with some form of cutter that forms the undercut. In others, the expanding part of the anchor is simply forced into the surrounding medium, so the anchor itself substantially fills and/or blocks off the entrance to the undercut area so as to stop flow of material past the expanded portion.